1. Field of the Invention
The present invention relates to apparatus and methods for displaying and manipulating information on a computer system, and more particularly, the present invention relates to a computer controlled display system and method employed on the display system for applications to provide collection browsers having a number of browser items for users' selective browsing.
2. Art Background
Today, many computer systems utilize direct manipulation graphical user interfaces in which many previously coded programming commands are replaced by graphic images, or icons, on a computer display. These graphic images, or icons, symbolically represent a variety of objects or operations the computer system will execute if the graphic images, or icons, are chosen. A user interacts with the computer by choosing and manipulating these graphic images, or icons.
Additionally, many direct manipulation graphical user interfaces utilize multiple windows displayed on the computer display for the applications to convey information to a user. The information is presented in a combination of text and graphics in these windows. Each window may take the form of a variety of objects such as a file folder, loose-leaf binder, or simple rectangle, and the windows may overlap one another with the "top" window fully visible and constituting the current "work file". The user may delete information from a window, move data from one window to another, and generally operate on the window as if an actual file in an office is being used. Thus, the user is permitted to operate on and manipulate the window contents, and the window itself, as if the image constituted an actual object.
For further description of graphical user interfaces, see, D. Robson, "Object Oriented Software System", BYTE, August 1981, p. 74, Vol. 6, No. 8; and L. Tesler, "The Small Talk Environment", BYTE, August 1981, p. 90, Vol. 6, No. 8. See also, U.S. Pat. Re. No. 32,632, reissued Mar. 29, 1988, and assigned to Apple Computer, Inc.; and U.S. patent application Ser. No. 07/323,774, filed Mar. 15, 1989, its corresponding Division and Continuation Applications, Ser. Nos. 07/458,596 and 07/619,665, filed Dec. 26, 1989 and Nov. 28, 1990 respectively, and Ser. Nos. 07/751,866 filed Aug. 28, 1991, now issued as U.S. Pat. No. 5,261,098, assigned to the assignee of the subject application, SUN Microsystems, Inc.
Although the various implementations of direct manipulation graphical user interfaces vary significantly for different machines manufactured by different vendors, the various methods by which a user interfaces with various applications are substantially consistent within a particular implementation. Typically, a window system is provided to facilitate applications in presenting information to the user and receiving inputs from the user, in a manner that is conforming to the particular implementation of direct manipulation graphical user interface. The window system commonly includes a number of window routines for performing various window functions, and a window manager which is given the responsibility of mediating competing demands from the applications for physical resources, such as screen space, color resources, keyboard.
Furthermore, a window toolkit is usually provided to shield the window routines from the application developers and to assist them in varying degrees to conform their applications to the particular implementation. The window toolkit commonly includes a centralized notifier which is given the responsibility of detecting and dispatching events, such as, keys on the keyboard being pressed, "mouse" movements, thereby alleviating the applications of the burden. The applications merely have to provide the various callback procedures for processing the detected events.
For further description of specific implementations of direct manipulation graphical user interfaces, for example, SunWindows.TM., by SUN Microsystems, Inc., or others by manufacturers such as International Business Machines, and Apple Computer, Inc., and their window systems and toolkits, the reader is directed to technical literature provided by these companies. (SunWindows.TM., is a registered trademark of Sun Microsystems, Inc.)
Thus it is desirable for the window toolkits to provide specific support for functions that are likely to be implemented in many applications, such as, collection browser. A collection browser is a data pane on which a number of browser items are graphically presented to a user for his selective browsing. Depending on the application, the browser items represented might be, for examples, printers, mail messages, workstations, files or people, and the user might select, "drag and drop" or "double click" on a browser item.
Today, applications typically receive little or no specific support for providing collection browsers. Since each application provides its own support, collection browsers are typically provided in manners that are not as consistent or as efficient as they could be. As will be described, the present invention provides an improved method and apparatus for applications to provide collection browsers in a manner that is more efficient, more consistent and improves over the prior art.